from django.http import HttpResponse 
from django.views.decorators.csrf import csrf_exempt

text=  """<form method="post" action="/add/">
    <input type="text" name="a" value="%d"> + <input type="text" name="b" value="%d">
        <input type="submit" value="="> <input type="text" value="%d">
        </form>"""

@csrf_exempt
def index(request):
    if 'a' in request.POST:
        a = int (request.POST['a'])
        b = int (request.POST['b'])
    else:
        a =0 
        b =0 

    return HttpResponse(text % (a,b,a+b) ) 




